Valve mechanism for pneumatic tools.



V. J. OBRIEN & R. O. AWKERMAN.

VALVE MECHANISM FOR. PNEUMATIC TOOLS.

APPLICATION FILED AUG. 27, 1910.

Patented Mar. 19, 1912.

3 SHEETS-SHEET 1.

iyg (:1 "001mg V. J. OBRIEN & R. C. AWKERMAN. VALVE MECHANISM FORPNEUMATIC TOOLS. APPLIOATION FILM; AUG 27, 1910.

1,020,6 l 9, Patented Mar. 19, 1912.

.Qvi l neoocs,

, warm u'uawfo I G HOT/"Cid 'throt tle valve mechanism ITE STATESsum-0mm n VINCENT J. O'BRIEN AND nor/IE0 c. AWKERMAN. or DENVER.COLORADO,- ASSIGNORS TO THE STANDARD ROCK TION OF COLORADO.

DRILL COMPANY. OF DENVER. COIZORADO, A CORPORA- VALVE MECHANISM FORPNEUMA-rrc room.

Specification or Letters Patent.

Patented Mar. 19, 1912.

Application filed August 27. 1910, Serial No. 579.332

To all whom it may concern:

Be it known that we. Vrxcn'x'rJ- OBlnex a-m'l Rom-1o. (l. .hvuuznuax,citizens of the lnited States. residing in the city and county of Denverand State of Cdlorado, have invented certain new and useful Tmprovemeats in Valve .\lechanisin"for Pneumatic Tools: and we do declarethe following to he a fulllclear, and exact description ofth'einvention. such as will enable others skilled in the art-'to which it.appertains to make and use the same; reference being had to the:u-conipanviug drawings. and to the letters and figures, of reference'niarked thereon, which t'ci n a part of this specification. j

Our invention relates"generally speaking ha-nnner.- This is a veryimportant feature when itisdesired to run the drill slowly or toreciprocate the hammer at a redu'c'ed speed as when the material to bedrilled is coinp u'atively soft, and under such circumstances it isexceedingly desirable that the feed bar be actuated by the motive fluidat a pressure reduced to correspond with that which is delivered to'thcdrill'cylinder.

Another 'featui-e of our improved construction" of valve mechanism isthat it allows a portion" of the motive. fluidwhich has been used topropel the hammer on its .forwardgmovement, to escape directly to theatmosphere. In explanation of this feature itfma'y be said that'it isquite common in to lH'lPIOYOlllQlllS in valvemeeh'anism tor:lllflCl'llIlQQfllllS class-to employ hollowcypneumatic tools, but morespecifically to for iOOlsUfilllS character in which a feed bar isemployed for holding the steel of a hammer drill against the rock.

One object of the invention is to providefia 't'onstruction whereby' itbecomes practicable to supply the feed bar casing with motive fluidunder pressure equal to that which is employed to operate the hammerwhich reciprocates in the cyllnde r of the machine.

In the construction common to this class of tools, the pressaire of themotive fluid which acts upon the piston of the feed bar, is

much greater thanthat whiclr'acts upon the hammer for reciprocating thelatter,'when the hammer is operating slowly. On this account the drillbitin the ordinary construction heretofore in vogue is'held against therock with much greater pressure than is desirable, under thecircumstances stated. In our improved construction the motive fluidwhich fed to the casing of the feed bar and to the drill cylinder, iscontrolled in such a manner that it passes to a chamber interposedbetween-the throttle valve' and the cylinder valve under only suchpressure as is necessary to reciprocate the hammer at motive fluidpassin from this chamber simultaneously to the fee bar casing and-thedrill cylinder. Hencethe delivered to. the feedbar passes to thecylinder for, reciprocating the lindrical valves having differentialpressure areas attheir opposite extremities, l the smaller o'li which isconstantly exposed to motive fluid'pressurc, and the largerinterni'it'tently e'Xposedthere-toin some stylesof these'tools themotive fluid which has been'nsed to pro pel the hammer on its for wardmovementiilsxtill used as motive fluid while passing to the atmospherein so far as it exerts a pressure against the larger area of thevalvesufiicient to overcome the constant pressure on the smaller area. 'Wehave. demonstrated inactual practice that the speed of a machineequippedwith the above'style-oi valve, can be increased ten per cent. or m re bythe use of an auxiliary exhaust controlled'by our improved throttlevalve. The reason is that the auxiliary exhaust results in a suddenweakening of presssure at theprecise time when it is needed, namely;when he hammer is stationary at the end'of itsf tirward stroke. andabout to start on itsretn'iyn trip.- Int-his event after the hammerhashioved a short portion ofits return trip,'it covers the auxiliaryexhaust portfso that'-the'etlect of motive fluid passii'i'g to theatmosphere from the larger areax of the cylinder valve is not changed;The I ,r'eason-th't the auxiliary exhaust of the aforesaid charactermust be controlled. by the thr0ttl ;valve,' is-that the auxiliary e15} ihaust musthot occurunt'rl the machine has re ched almost. its maxim m sr Iii exhaust b gll edj o e ters isestlr o, the

60 1n the valve-block 15. The smaller extrem-.

atmosphere the machine will not work well whilerunning at a slow speed,hence the nerecess 19 which is in communication with a conduit 20 whichscrewed nto the valve cessity for controlling it by 'theuse of the blockas shown at 21 and registers with the throttle-valve so thattheauxiliary exhaust is only employed whenthe machine is .running-"atpractically/its maximum speed. I

Having briefly outlined our improved connalcd; This conduit supplies themotive fiunl for operatmg the reciprocating hammer aswell as that whichacts upon the feed Sta-notion, we will proe edZt d s ib the bar forautomatically maintaining the drill trated'an em hodiment thereof.

In this drawing: Figure 1 1s a fragmentary section taken through ahammer drill equipped with our improved throttle valve construct on, apart of the hammer cylinder chamber 251:0 a supply chamber 28 formed Thevalve block is provided with three ports 22, '23 and 2 re 25 to thechamber 12 in which the feed bar reciprocates; and also with passages 26and 27, the passage 26 leading from the valve and a part of the feed barconstructio being in the valve block adjacent the valve mechaoff fromthe feed bar and the hammer cylinder, the feed bar chamber beingincommunication withqthe' atmosphere;, for exhaust-purp'oses. Fig. .2 is asim lar v ew llustrated. In this view the throttle valve n sm] andcommunicating with passages 29 is so adjusted that the motive fluid is'cut formed in the casing 30 and inclosing the valve mechanism 7. Thepassage 27 also leads from the valve chamber 251a) the sup-' ply chamber28. This chamber-28 enables us to obtain a number of advantages in theopening in which the valve piece'is' jour- 'specti-vely leading from thevalve chamber a showing'the throttleHvalve-in a: diflerent' operationofthe machine. Among these are position, namely, that in which the motivethe follow ng: Since the motive fluid passes fluid is delivered to'thefeed bar .chamber,. from this chamber toboth the engine and but cut oiffrom the hammer chamber Fig.

to a chamber interposed between the cyl1nder valve and the throttlevalve, the-motive v fluid passing from the said chamber to the cylinderchamber andfeed her 1' chamber 'in the motive fluid in such a mannerthat no pose; Figs. 4and 5' are 1 sections taken feed bar casing, thepressure must be the ,3 is a similar view-in-which the motive fluid.samein both and will always be proportionis cutoff from directcommunication with;

m a the feed bar casing to the requirement for holding-the drill againstthe rock. This feature has been already mentioned. lhis 1 chamber 28also makes it practicable to andle the dirt and foreign matter containedharm results to the delicate valve mechanism 'of the engine, since thedirt contained through the throttle -valve mechanism onin the motivefluid passes to the engine at lines 4- 4 and 5-5 respectivelyfof Fi'giafi2.'

Figs. 6 and 7 are sections taken on the and is much less injurious tothat part than 7-7 Fig. 2, showing the throttle valvezn when it isallowed to accumulate in the feed two difi'erent positions. Fig. 8'is asect-ion bar casing inwhich latter event it is extaken through a hammerdrill cutting the oeedingly injurious tothe feed bar'mech'athrottlevalve mechanism, the parts, being nism at all times and to the valvemechanism shown in the position illustrated in Fig. 7, of the enginewhenever the position of the exhaust. Y Y

- to permit the employment of theau iliary engine is changed so that thefeed bar (as ing is above, whereby the accumulation of The samereference characters indicate the dirt and foreigmparticles of matter isalsame partspin all the'views.

Let the'numeral 5 desi ate the cylinder;

tively large quantities.- Furthermore'this 6 the hammer; 7 the va vemechanism for chamber enables us to obtain the most speedy cont-rollinthe supplygi and exhaust to and andsensitwe coactiorr between thepressure from the ammer c'ylinder; 8 the casing m which the piston 9 ofar feed bar 10 is mounted to reciprocate, Interposed between the valveand inthe teed bar and t e speed of the motor;

he'consuming capacity of the valve mechanism and the chamber-.12 ofmotor are the only factors provided for.

the feed bar is our improved throttlevalve reducing the pressure in the.feed-bar casing,-

mechanism, which maybe designated in its .it is found in practice thatthedei-red reity [1'6 ofthisvalve piece protrudes beyond the valve blockand is equipped with an op t the crating head 17 which issecnred'theret-o by M sult is attained to the maximum degree by theemployment of this chamber. There is still another very importantfeature of advantage resulting-fromthis chamber since the machine is'sebalanced that the-vibract' that in our construction the mofluid is firstallowed to pass to the and since a partial 0 using of thethrottle 'tionis igreatly reduced. Attention is called once and in comparatively smallquantities,

lowed to pass into the engine in comparaa set bolt 18.' In the basefofthis valve is a chamber 28 in the head block. It passes I thence inopposite directions lothe feed bar t the cylinder, thus opening acontinuous pascasing and engine respectively. This gives! a balancedresult/because ot' the fact that From the foregoing description the usethe motive fluid is passing simultaneously in oppcsite directions to thetwo instrumentalities, the force of theflmd in opposite directionshaving a neutralizing effect and greatly. reducing the vibration ascompared with the result in those constructions in which the motivefluid passes first to the feed bar casing and immediately acts orproduces a tendency to move the machine in the rearward direction so faras the instability of its support will permit, and then as the-fluidpasses in the opposite direction,

there is a resultant vibration produced which is entirely absent in ourconstruction. The valve piece 14 is provided with 3 U-shaped passage 31formed in its upper portion and adapted when the valve piece is properlyadjusted to register with the passage 24, whereby the motive fluid fromthe chamber 12is allowed to escape to the atmosphere, the passage 31bein continued through the operating head ofthe-valve piece as shown at-32. The valve piece 18 also provided-with a passage 33 extendingtransversely therethrough and adapted when the valve is properlyadjusted to register with the.-passages 22 and 26 of the valve bloclt,.to allow the motive fluid to pass from the chamber 28 to the feed barchamber 12 simultaneously with its passage from the supply chamber 28 tothe cylinder chamber for operating the hammer.- The valve piece isfurther provided with a port 34 which when the valve is in the positi n.to cause its passage 33 to register with t e passages 24 and 26, iopenscommunication between the annular recess 19 of the valve piece and thepassage; 2 of the valve block, thus allowing the motive fluid topassfreely from the supply con'dtiit 20 to the supply chamber 28. The valveblock is also provided-with passages 35 and '36, the lattercommunicating at ,its forward extremity withan exhaustpassage 37 formedin the.

wall of theeylinderlieand the casing 30 of the valve mechanism; 7,: thefor'warrtextremity of the assage 37 communicating by a port 38 with thecylinder chamber 39 just in {the rear of the rear-extremity of thehammer 6 when the latter is at or ap' proximately at its forward limitof move ment. .The rear-extremity of the passage- 36 communicates asshown at 40 with the valve chamber 25.

l the. chamber 25 as shown at 41, and at its ,shown at 42. When thevalve piece 14 is rear extremity with the atmosphere as properlyadjusted a cavity 43 formed there- The passage 35 com-- "mnnicates atits forward extremity with sage from the forward portion'of the cylinder to the atmosphere.

and operation ot'ourimproved throttle valve this case the mot ivctluid'is cut ofi' from the first be turned to the position shown inFigs.

'2 and 5, in which event a short passage 4% formed in the valve pieceplaces the passage 23 of the valve block in communication with theannular recess 19 of the valve, thus allowing the motive fluid to passto the feed bar chamber 12. whereby the drill bit is pressed against thebreast of the rock preparatory to the commencement of the drilling work.Now in order to start the hammer the throttle valve is given a furtherpartial rotation as indicated in Fig. 6. whereby the passages 23 and-4tare cut off from theinotivetluid, the valve piece, however, being turnedsufficiently to allow the motive-fluid to pass tothe chamber 28 throughthe wort 34 of the valve, through the passage 2t ot' the valve piece,and thence from the chamber 28 through the passage 26 of the valveblock, the passage 33 of 'the valve piece, and the passage 22 of thevalve block to the feed bar chamber 12. As illustrated in Fig. 6,however, the passage 33 of the valve piece is only partially placed inregister with the passages 22 and 26. In this event the hammer will heslowly reciprocated and the-auxiliary exhaust is not employed, since thepassages.

35 and 36 are not placed in communication, the cav1ty'43 not being 111position to con- ,nect the passages 35 and 36. Now it it is desired torun the drill at maximum speed, the valve piece Will be given a furtherpartial rotation in the same direction, whereby the passage 33 of thevalve piece is placed in full register with he passages 22 and 26 of thevalve block, the port 34 of the valve piece and the passage 27 of thevalveblock being also simultaneously placed in full register to allowthe mam'mum quantity ofmotive fluid to pass from the supply conduit 20to the supply chamber-.28, and thence to the cylinder chamber 29 and thefeed bar chamber 12. In this event the movement of the valve piece alsoplaces the cavity 43 in position to connect the passage 36 with thepassage 35,'thus openin a. continuous exhaust passage from the orwaivlportion of the cylinder chamber to the atmosphere by way of the port38,.the-pw chamber to the said casing.

said chamber being arranged to constantly is in, operation, thevalve-and head block with a feed bar casingand a drilling engine,-

means for delivering and throttling the mobar casing and -of a headblock interposed between the feed cation with the engine and feed barcasing,

sa es 37 of the valve cylinder, the passage valve piece and the passage35 of the valve block." Under these clrcumstances the hammer (3 will bereciprocated'at its maximum? speed and the auxiliary exhaust will beutilized as heretofore explained.

Having thus described our invention, whatwe claim is:

1. In a pneumatic tool equipped with a 5 feed bar casing .a pistonmovable therein and l a motor, the combination of a head block casingfor constantly supplying motive fluid 1n common to both the said casingand said motor when the latter is in operation, and

tive fluid on its way from the sourceof supply to said chamber, thelatter being locah d on the'opposite side of the throttling means fromthe feed bar casing, the head block having a passage leading from thesaid '2. In a hammer drill equipped witha feed bar casing and an engine,the combination of a heat block interposed between the feed said engineand having a relatively large chamber in comnmnication with the engineand feed bar casing, the

supply motive fluid in common to both the said casing and said enginewhen thelatter is in operation. the heiid block having a passage'leadingfrom said chamber to the teed bar casing, and means located between thesaid chamber and said casing for delivering and throttling the motivefluid on its way to the said chamber.- I

3. 'In a hammer drillequipped with a feed; bar casing and an engine, thecombination bar casing and said-engine and having a relatively large.chamber in communication with the engine and the feed bar casing, thesaid chamber being arranged to constantly. supply motive fluid in commonto both'the Saideaing and said engine when the latter having passagesleading from the said chamher to thesaid casing, and athrottlevalveloeated int-he head block for controlling the motive fluid on itsway to the said chamber, the latter being located between the said valveand the engine. i

4. In a tool of the class described equipped theeombination of a-blockinterposed between s'aid-easing and said engine and hay; ing arelatively large chamber in communisaid chamber arranged to constantlysupply motive fluid incommon to both the feed bar casifigland saidengine when the latter purpose set forth.

is in operation, a valve journaled in said block for throttling themotive fluid on its 36 of the valve'bloek, the cavity 43 of the way tosaid chamber. the latter being 10- A thesaid .valve and the saidthrottle valve mourited n said block, the? latter being provided withpassages located on opposite sides of th'evalve, and a'rela-' tivelylarge chamber in communication with the engine and 'feed barcasing,'the"said chamber being arranged to constantly suppl v motivefluid 1n commonftoboth the feed bar casing and-engine when the latter isin o eration, the said chamber being located one of said passagesin thehead block extend ng toward the engine and communirating with the saidmotlve fluid supply between the throttle valveand the'engine,"

chan bcr while'the other passage is located valve and head block havinga passage for the siupply of motive fluid to the said cham-- her,the.valve having a passage adapted to on o posite'sides of the valve,when the eugme is, in operationz' reginter with the passages in theheadblock (3. In a tool of the class described equipped with a feed barcasing and a drillcylinder, the combination of a head block sages forsimultaneously regulating the sup-.

plv of motive fluid to the feed bar casing interposed between the said.casing and ovhiu ler, and a on the opposite side of the valve and. incoml i nnnneation with the feed bar casing, the

and the drill cylinder, ahd fora'cgulating the cxhaustfrom the feed barcasing and drill c vlinder.- 4 p 7. In a toolof the class describedequip ed with a feed bar casing and. drill'eylin er, the combination ofa h'cad block interposed between the said casing and said cylinder, ortsand passages located in the valve and head block for simultaneouslyregulating the supply of motive -fini'd to the drill cylinder and feed,bar casing as the valve is my tated,-the head block also'havingexhaustpassages which: are arranged to be placed in communicationwith eachother when the valve is adjusted, the latter having a cavity for thepurposelwhen it is placed in position,

tov deliver themaxiinum supply of motive fluid to the feed bar cas'ingand drill cylinder, the said exhaust passages being in co'mmunicationwith the drill cylinder for the S. in a tool of the class describedequipped with a feed bar casing and a drill cylinder.

the combination of a head block interposed between the -feed bar casingand drill cylinder, a throttlevalve rotatably mounted in said bloc k,and exhaust passages 'formed' in the said block, the said valve having acavity adapted when the valve is properly adjusted to place the saidpassages in communication with each other, the wall of the drillcylinder having an exhaust passage leading from the forward portion ofthe cylinder and communicating with one of the exhaust passages in thehead block.

9. In a tool of the class described equipped with a feed bar casing anda drilling engine, the combination of a head block interposed betweenthe said casing and said engine, a valve mounted to rotate in saidblock, the valve and head block having passages for successivelyregulating the supply of motive fluid troni the source of supplydirectly to said feed bar casing forsetting the drill againstthe rdckand placing the feed bar casing in communication with the atmosphere forexhaust purposes, the head block having a relatively large chamberlocated adjacent the engine, the alve and head block having passages forconducting the motive fluid from the said chamber to the feed barcasing. for constantly supplying motive fluid to-the teed bar casingwhen the engine is in operation, means for throttling the motive fluidon its way to the said chamber, the'latter being external to the throt-'tling means.

10. In a tool of the character described equipped with a feed bar casingand a drilling engine, the. combination of a head block interposedbetween the said casing and said enginmfand the head: block having arelatively 'ela'rge chamber located adjacent the enginefand incommimication with the engine and feed bar casing, for supplying motivefluid in common to the said chamber and said engine, and a throttlevalve rotatably mounted in said block, the valve and head block beingequipped with passages for simultaneously admitting motive fluid to saidchamber in the head block and from said chamber to the feed bar casing,and for successively admitting motive fluid directly to the feed barcasing to set the drill against the rock and for placing said casing incommunication with the atmosphere for exhaust purposes.

11. In a tool of the class described equipped with a feed bar casing anddrill cylinder, the combination of a head block interposed between thesaid casing and cylinder and a throttle valve rotatably mounted in saidblock which is supplied with a relatively large'chan'iber adjacent thedrill cylinder, the valve and head block having passages for conductingmotive fluid to the feed bar casing to set the drill against the rock,and for simultaneously regulating the supply of motive fluid from saidchamber to the feed bar casing. the latter being also in communicationwith the said chamber, the valve and head block also having passages forregulating the exhaust from the feed bar casing and drill cylindersubstantially as described.

12. In a tool of the class described equipped with a feed bar casing anddrill cylinder, the combination of a head block interposed between thesaid casing and said cylinder, ports and passages located in the valveand head block for delivering motive fluid tothe t'eed bar casing to setthe drill against the rock, and for simultaneously regulating the supplyof motive fluid to the drill cylinder and teed. bar casing as the alveis rotated, the head block also having exhaust passages which arearranged to be placed in communication with each other when the valve isadjusted to deliver the maximum supply of motive fluid to the feed barcasing and drill cylinder, the valve having a cavity for the purpose,the said exhaust passages being in communication with the drill cylinderfor the purpose set forth.

In testimony whereof we atlix our signatures in presence of twowitnesses.

VINCENT J. (YBRIEN.

tOMlfit) (I. IUVKERMAN. lVitnesses:

A. J. BRlEN,

F. E. BOWEN.

